Help me decide which Fuji camera and lens

Hi all,
i have a Holiday planned ahead and would like to take a Fujifilm camera along with me. i am heading to the Philippines where i go to beaches , meet many family members , friends, low light comedy bars, house party etc. i will be doing plenty of family and friend group pics therefore i am thinking a fast lens would be no use for me.. however, i would need the camera to focus at dark places... i would also like something lighter and cheap

1) do you think 18mm f2 or 23mm f1.4 would be better for my purpose? i already have a zoom 55-230mm.

2) i can find a used X-T1 for £400 (body, battery and charger) and a x-e2 for £300. comparing both of them, i don't see much difference apart from the fact that the x-e2 actually has a small built in flash which could be very very useful for me as the x-trans sensors just go as high as 6400 Raw. But is the flash on the x-e2 good enough to leave the X-T1 ?

I have the x-e2 and really like it, although the x-t1 has a few technical upgrades that might be worth the extra money.
your overall budget may really be the determining factor in which body/lens combo you get.